What is TM 21? How it is different from LM 80 and LM 79?

What is TM 21? How it is different from LM 80 and LM 79?

In this topic, we are going to discuss “What is TM 21”? “ How it is different from LM 80 and LM 79?”

LEDs are like other light sources, see their output decline over time. However, given the remarkably long life of LEDs and the absence of visible signs indicating their decreasing performance, it can be more complex to accurately measure and communicate light output over time. To help address this issue, the Illuminating Engineering Society of North American (IESNA) and the Environmental Protection Agency (EPA) have put in place standards for reporting the useful lifetime of an LED package: LM-80 (Measuring Luminous Flux and Color Maintenance of LED Packages, Arrays and Modules) and TM-21(Projecting long-term Lumen Maintenance of LED Light Sources).